Chapter 5Chapter 5Page 124 Page 124

How Ecosystems How Ecosystems WorkWork

All ecosystems do 2 things:All ecosystems do 2 things:

1. Transfer Energy1. Transfer Energy

2. Cycle matter2. Cycle matter

Transfer EnergyTransfer Energy

(Most ecosystems use (Most ecosystems use SunlightSunlight as its source, but as its source, but some use some use inorganic moleculesinorganic molecules))

Moves from:Moves from: Sun – it’s source – into organisms – then into Sun – it’s source – into organisms – then into

space as heat.space as heat.

Transfer of MatterTransfer of Matter

RecycledRecycled Carbon, oxygen, and other elementsCarbon, oxygen, and other elements

5.1 Energy Flow in Ecosystems5.1 Energy Flow in Ecosystems

Each living thing in the environment plays a Each living thing in the environment plays a different role in the flow of energy and matter.different role in the flow of energy and matter.

ProducersProducers

““organisms that make organisms that make their own food from their own food from inorganic molecules and inorganic molecules and energy”energy”

PLANTS!PLANTS! Create sugars thru Create sugars thru

PHOTOSYNTHESISPHOTOSYNTHESIS

Carbon Dioxide + LE + Carbon Dioxide + LE + water = glucose + water = glucose + oxygenoxygen

TYPES OF PRODUCERSTYPES OF PRODUCERS

TERRESTRIALTERRESTRIAL Plants are the most Plants are the most

important producers important producers

AQUATICAQUATIC Small photosynthetic Small photosynthetic

protists and bacteria are protists and bacteria are the main producers the main producers

Few nonphotosynthetic Few nonphotosynthetic producers like bacteria producers like bacteria that live in harsh envt’sthat live in harsh envt’s

Strange producers!Strange producers!

Some producers don’t even use light!Some producers don’t even use light! They use Chemicals insteadThey use Chemicals instead Ex – Tube worms Ex – Tube worms

in the deep seain the deep sea

They use hydrogen sulfideThey use hydrogen sulfide

Ways to gather food…Ways to gather food…

ProducersProducers ConsumersConsumers DecomposersDecomposers

CONSUMERSCONSUMERS

““organisms that cannot organisms that cannot make their own food”make their own food”

Ex - Animals, fungi, Ex - Animals, fungi, protists, bacteriaprotists, bacteria

Obtain energy by eating Obtain energy by eating other organismsother organisms

4 TYPES OF CONSUMERS4 TYPES OF CONSUMERSpage 127page 127

HERBIVOREHERBIVORE

““eats only producers”eats only producers”

Insects, cows, etcInsects, cows, etc

CARNIVORECARNIVORE

““capture and eat herbivores or capture and eat herbivores or other carnivoresother carnivores

Secondary consumers, etc.Secondary consumers, etc.

Adapting to hunting, capturing, Adapting to hunting, capturing, and eating preyand eating prey

OMNIVOREOMNIVORE

““eats both producers and eats both producers and consumers”consumers”

HumansHumans

Primary consumer, 2ndary Primary consumer, 2ndary consumerconsumer

SCAVENGERSSCAVENGERS

““don’t hunt living prey, but don’t hunt living prey, but feed on dead orgs.”feed on dead orgs.”

Dead plants, animals,etcDead plants, animals,etc

Begin the return of nutrientsBegin the return of nutrients

DecomposersDecomposers

““Consume the bodies of dead organisms and Consume the bodies of dead organisms and other organic wastes”other organic wastes”

Ex – bacteria, fungiEx – bacteria, fungi Recycle nutrients back to the soil Recycle nutrients back to the soil Complete the cycle of matterComplete the cycle of matter

Food ChainsFood Chains

““A series of different organisms that transfer A series of different organisms that transfer food between the trophic levels of an food between the trophic levels of an ecosystem”ecosystem”

FOOD WEBFOOD WEB

“ “Network of food chains Network of food chains representing the feeding representing the feeding relationships among the relationships among the organisms in an organisms in an ecosystem”ecosystem”

FOOD WEBFOOD WEB

Includes all the food Includes all the food chains in an ecosystemchains in an ecosystem

Webs don’t usually Webs don’t usually show the show the decomposersdecomposers at the top of the web.at the top of the web.

Changes in the Changes in the population of one population of one organism can affect organism can affect many other populations.many other populations.

Diversity and StabilityDiversity and Stability

Some biologists think that a food web with Some biologists think that a food web with MORE links can withstand changes/instability MORE links can withstand changes/instability better than one with only a few links.better than one with only a few links.

TROPHIC LEVELSTROPHIC LEVELS

““layer in the structure of feeding relationships layer in the structure of feeding relationships in an ecosystem”in an ecosystem”

Food ChainsFood Chains

ALWAYSALWAYS begins with begins with PRODUCERSPRODUCERS on the on the bottom (usually plants)bottom (usually plants)

Next layer would Next layer would contain the contain the HERBIVORESHERBIVORES

Next layer(s) would Next layer(s) would contain contain CARNIVORESCARNIVORES

Ecological PyramidEcological Pyramid

““diagram that shows the diagram that shows the relative amounts of relative amounts of energy in different energy in different trophic levels in an trophic levels in an ecosystem”ecosystem”

Can show energy, Can show energy, biomass, or number of biomass, or number of orgs.orgs.

BiomassBiomass

““TOTAL AMOUNT OF TOTAL AMOUNT OF ORGANIC MATTER ORGANIC MATTER PRESENT IN A PRESENT IN A TROPHIC LEVEL”TROPHIC LEVEL”

BIOMASSBIOMASS

Basically, biomass is the potential food for the Basically, biomass is the potential food for the next trophic level.next trophic level.

Most energy is lost before it is passed to the Most energy is lost before it is passed to the next trophic level.next trophic level.

This loss of energy explains why there is a This loss of energy explains why there is a limit to the number of trophic levels an limit to the number of trophic levels an ecosystem can support.ecosystem can support.

BioaccumulationBioaccumulation

Is a process resulting in Is a process resulting in the concentration of the concentration of substances in living substances in living tissues.tissues.

Used to reference Used to reference chemical contaminants chemical contaminants that may do harm to that may do harm to organims like pesticides organims like pesticides or heavy metals.or heavy metals.

Biological MagnificationBiological Magnification(On page 312)(On page 312)

““the increasing the increasing concentration of a pollutant concentration of a pollutant in organisms at higher in organisms at higher trophic levels in a food trophic levels in a food web”web”

Pollutants become Pollutants become concentrated in the bodies concentrated in the bodies of consumers the higher up of consumers the higher up the chain it goes SINCE the chain it goes SINCE THEY EAT MORE!THEY EAT MORE!

Therefore intake of a few Therefore intake of a few organism can affect the organism can affect the whole food web.whole food web.

5.2 The Cycling of Materials5.2 The Cycling of Materials(page 132)(page 132)

Carbon CycleCarbon CycleNitrogen CycleNitrogen CyclePhosphorus CyclePhosphorus Cycle

Carbon CycleCarbon Cycle

Early earth = 95% COEarly earth = 95% CO22

Now is only .04% thanks to photosynthesisNow is only .04% thanks to photosynthesis Present in 3 main sources: Present in 3 main sources:

(aka CARBON SINKS)(aka CARBON SINKS) 1. living things1. living things 2. oceans = CO2 dissolves in water easily2. oceans = CO2 dissolves in water easily 3. rocks = fossil fuels3. rocks = fossil fuels

Short Term VS. Long Term Short Term VS. Long Term SINKsSINKs

Short TermShort Term- Cycles through a Cycles through a

lifetime through the lifetime through the food webfood web

Long TermLong Term- Millions of years- Millions of years-Ex – fossil fuelsEx – fossil fuels

Nitrogen CycleNitrogen Cycle

Living things need Nitrogen to make Amino Living things need Nitrogen to make Amino Acids = ProteinsAcids = Proteins

Can’t use the N gases present, but in a Can’t use the N gases present, but in a different form.different form.

Therefore Nitrogen Fixation must occur!Therefore Nitrogen Fixation must occur!

Nitrogen FixationNitrogen Fixation

Use the N gases to make ammonia(NHUse the N gases to make ammonia(NH33) )

which plants can usewhich plants can use Nitrogen- fixing Bacteria Nitrogen- fixing Bacteria Some bacteria live on plant roots. These Some bacteria live on plant roots. These

plants are called plants are called LEGUMESLEGUMES. (peanuts, beans). (peanuts, beans)

Phosphorus CyclePhosphorus Cycle(page 135)(page 135)

Is part of our cell compositionIs part of our cell composition Plants get phosphorus from soil and waterPlants get phosphorus from soil and water Animals get it from eating plants or other Animals get it from eating plants or other

animals that ate plantsanimals that ate plants

Too much Phosphorous?!Too much Phosphorous?! Too much P from fertilizer has caused major Too much P from fertilizer has caused major

algal blooms algal blooms which dies, then loss of oxygen, which dies, then loss of oxygen, and then suffocates the life in the water and then suffocates the life in the water

Ecological Ecological SuccessionSuccession

= is a gradual process of change = is a gradual process of change and replacement of some or all and replacement of some or all of the species in a community.of the species in a community.

5.2 How Ecosystems Change5.2 How Ecosystems Change(page 137)(page 137)

Ecological SuccessionEcological SuccessionPrimaryPrimary SecondarySecondary

Primary SuccessionPrimary Succession Occurs on a surface Occurs on a surface

where NO other where NO other ecosystem existed ecosystem existed beforebefore..

Uses a pioneer Uses a pioneer species to break species to break into the new into the new community!community!

ExamplesExamples:: Volcano eruptionVolcano eruption New islandNew island

Pioneer Species:Pioneer Species:

First thing in the area to help break down rocks and turn into soil.

Ex - Lichens

Succession and soilSuccession and soil

Secondary SuccessionSecondary Succession Occurs on a Occurs on a

surface where an surface where an ecosystem HAS ecosystem HAS previously existed.previously existed.

More commonMore common

Examples:Examples: FireFire Tornado/HurricaneTornado/Hurricane Shopping centerShopping center

GrassesGrasses

Small greenery Small greenery is the first things is the first things in the area after in the area after soil has been soil has been established.established.

Small ShrubsSmall Shrubs

Shrubs and bushes Shrubs and bushes begin to grow in the begin to grow in the area. area.

They are more They are more complex than small complex than small grasses since they grasses since they have woody stems as have woody stems as well as greenery.well as greenery.

Pine Trees are some of the first Pine Trees are some of the first trees to move into an area trees to move into an area because of shallow roots.because of shallow roots.

Hardwood trees will move in nextHardwood trees will move in next

After smaller trees After smaller trees have established have established themselves, larger themselves, larger more complex more complex trees (hardwoods) trees (hardwoods) will move into the will move into the area last.area last.

Climax CommunityClimax Community

The oldest and most The oldest and most complex group of complex group of organisms that move organisms that move into a community after a into a community after a disturbance.disturbance.

Most communities Most communities never reach their ideal never reach their ideal CC because of CC because of disturbances – either disturbances – either natural or human madenatural or human made

Climax community and Climax community and successionsuccession